Stimulus categorization by brain-damaged patients

Patients with localized insult to the right hemisphere, or to either the anterior or the posterior portion of the left hemisphere, as well as neurologically intact controls, evaluated stimuli on a seven-point rating scale for their degree of category membership. The stimuli were taken from one of two continua, one composed of fruit and vegetable items, and the other of items differing in hue and shape. Different subsets of stimuli provided different contexts for the judgments of category membership. The two left-hemisphere groups showed anomalies in categorizing the fruit and vegetable items but not the perceptual items, while the reverse was true for the right-hemisphere patients. Moreover, both left-hemisphere groups demonstrated context effects in their judgments of the representativeness of the fruit and vegetable items, but differed in the way in which they responded to changing contexts. Left posterior patients demonstrated weak category boundaries and even reclassified items. In contrast, patients with left anterior damage showed highly categorical responses and less differentiation of items within a category. All groups showed striking context effects in judgments of perceptual items in terms of changes in representativeness ratings and the location of a category boundary. Alternative interpretations of the results are offered.     

Commitment to Particiation in Musical Activities: An Extension and Application of the Investment Model1

Recently, an investment model integrating several interdependence-type variables has been proposed to explain commitment in social and organizational settings. The model includes the components of costs, rewards, investments, and alternatives, and has served well in predicting specific outcomes such as job turnover and romantic commitment. The purpose of the present study was to determine the degree to which the investment model can be extended to a new area—commitment to musical activities—and to assess the extent to which commitment profiles generated by the model vary across musical preference groups. Results from a sample of 87 musical devotees demonstrated that the investment model is a valid means of accounting for commitment to participation in musical activities. In addition, distinctive profiles for each group—classical and nonclassical—were identified.     

The Sum and Substance of It: The Appreciation of Mass and Count Quantifiers in Parkinson′s Disease

We performed three experiments in order to determine whether patients with Parkinson′s disease (PD) have a sentence comprehension impairment. In the first experiment, we found that nondemented PD patients were impaired at matching a short sentence containing a mass or count quantifier (e.g., "Point to the jar with many") with one of four pictures. Patients erred by pointing to the incorrect mass or count type of substance, but pointed correctly to the large or small amount of a substance in the picture. In the second experiment, we asked the same PD patients to judge short sentences containing mass or count nouns modified by mass or count adjectives (e.g., *"The glass contains many milk"). PD patients were significantly impaired at detecting errors in the agreement between a noun and a quantifying adjective and errors in the appropriate use of the plural associated with a noun. A sentence completion task was performed in order to determine whether patients impaired on both sentence-picture matching and sentence judgment tasks are also compromised in their expression of quantifiers. Some patients impaired on both tasks also had difficulty expressing quantifiers, and it is these patients who may have difficulty performing grammatical computations. Other patients were selectively impaired in their sentence-picture matching or their sentence judgments, suggesting a performance deficit concerned with a particular task. We conclude that sentence comprehension impairments in PD are multifactorial in nature.     

Verb Comprehension Deficits in Probable Alzheimer's Disease

Studies of lexical comprehension in probable Alzheimer's disease (pAD) have focused almost exclusively on nouns. In the following preliminary study, we examined whether lexical comprehension for verbs is also impaired in 25 pAD patients. The semantic meaning of motion verbs, cognition verbs, and perception verbs was assessed with a triadic comparison task. Structural meaning associated with these verbs was evaluated by asking the patients to judge the coherence of sentence frames that accept these verbs naturally or awkwardly. We found that pAD patients are significantly impaired at identifying semantic relations among verbs. pAD patients also encountered significantly more difficulty judging the coherence of sentences than control subjects. Correlation and regression analyses demonstrated that semantic characteristics of verbs are projected from the verbs' sentence frames in control subjects, but there was minimal evidence for such a structural–semantic relationship in pAD. We consider several possible explanations for our preliminary observations of an impairment that has consequences for processing both semantic and structural aspects of verb meaning.     

Pain, aggression, fantasy, and concepts of sadomasochism

Traumatized infants and children may exhibit syndromes of aggressive, pain-seeking, and self-destructive behavior resembling the so-called sadomasochism seen in adults. Three hypotheses are offered to account for the repetition of sadomasochistic phenomena in childhood and later character disorders: 1) pain and painful affects are sources of aggression; 2) the need to control aggression plays an important role in the development of psychic structure; 3) child abuse and trauma impair the ability to use fantasy for the mastery of impulses. Difficulty in expression and control of aggression are central issues in character disorders.     

Initiation of dates and anxiety among college men and women

A dating questionnaire was completed by 248 undergraduate college students who were either dating someone in an exclusive relationship or were not going steady. Responses to this questionnaire by students not going steady with someone indicated that 54 college-age men were more active at initiating and more successful at getting dates than the 70 women. However, between one-half and three-fourths of the college women reported having initiated dates with men. Both sexes experienced considerable anxiety while initiating a date which suggests a self-help system might be designed to ameliorate this problem.